The present invention relates to a chemical control system for confining volatile fluids and especially to a chemical control system for confining dry cleaning fluids from a dry cleaning machine in a dry cleaning facility.
Dry cleaning plants are commonly provided throughout the country for cleaning of clothes and fabric materials. Dry cleaning plants are typically small operations and there are approximately 30,000 dry cleaning establishments in the United States, most of which are small businesses using large volumes of hazardous material. This makes the industry one of the largest groups of chemical users in general contact with the public. In addition, employees of dry cleaning establishments typically have little training in the use of hazardous materials. Most of the dry cleaning establishments in the U.S. use a volatile liquid, perchlorethylene (Perc.), which is heated and used in a dry cleaning machine within the establishment to clean the clothes or fabric without the use of water. A typical retail dry cleaning establishment has a dry cleaning machine, usually a dry dry machine, which uses approximately 100-150 gallons perchlorethylene along with associated equipment which might include a distiller unit, a solvent filter unit, associated piping condenser unit, a vent system from the dry cleaning unit to the outside, and a waste perchlorethylene storage area. Regardless of the care exercised by the operator, the perchlorethylene is routinely released in small amounts from the dry cleaning machine and associated units under normal operation. Perchlorethylene is released as a liquid from pipe failure and from the operation of the dry cleaning machine in which the volatile liquid is released in fumes upon the opening of the door to the machine for the insertion or removal of fabrics and clothing. Vapor is also released during the changing of the filters and in other activities in the dry cleaning establishment. Perchlorethylene vapors are released to the atmosphere both as fugitive emissions from spills and normal operations and through the ventilation system which is normally built into each dry cleaning machine. In addition, liquid perchlorethylene, when released, can penetrate through concrete floor slabs resulting in contamination of the soil and groundwater. Such contamination results in significant financial hardships for dry cleaners, land owners, and financial institutions holding mortgages since it may result in making it difficult to sell the property and the costs of cleanup can be costly. Perchlorethylene released as vapor within the dry cleaning facility results in health and safety risks for workers as well as a general risk to the public through fugitive and vented atmospheric release of vapor.
The present invention is directed towards a system for preventing or reducing the escape of liquid perchlorethylene or other dry cleaning chemicals through vapors in the operation of machinery as well as through liquid spills or the like and which can be rapidly retrofitted to existing dry cleaning equipment to contain both liquid and gaseous emissions and also is sufficiently modular that different portions can be used and expanded to add other portions and uses a low pressure air current with a discharge in predetermined areas and a collection of the air from the air curtain along with vapors into a system for filtering out the perchlorethylene vapor. The system provides an electronic monitoring system for monitoring and controlling the system in addition to an in situ system for monitoring, confining, and cleaning the subsurface areas below dry cleaning equipment.
In the past, there have been a wide variety of systems which used a controlled flow of air for preventing contamination within a predefined area and these include the following U.S. Patents. The Guice U.S. Pat. No. 4,133,255, teaches a paint spray booth and method of painting an article therein in which air under pressure is discharged above a painting booth to surround a car being painted to remove paint laden air from the booth into plenums positioned at the ground level of the booth. The Davis et al. U.S. Pat. No. 4,267,769, teaches a prefabricated knock-down clean room which moves air under pressure through a filter media to remove micro-organisms from the air. The Lindestrom U.S. Pat. No. 3,726,203, teaches a device for maintenance of a dustfree, bacteria-free zone in a room which creates a separate zone with an unbroken air curtain around the zone. The Truhan U.S. Pat. No. 3,776,121, is for a controlled environmental apparatus for industry which uses a plurality of controlled outlets for directing treated air downward at a rate progressively increasing in volume from the center of the control zone outwardly and has a plurality of inlet plenums spaced at the floor level at control points for redrawing in air to be filtered. The DeVecchi U.S. Pat. No. 4,427,427, is for a vertical laminar flow filter module which provides a work area of ultra high efficiency air filtration in which the perimeter of the work area has a curtain of air enclosing the area. The Allander U.S. Pat. No. 3,380,369, is a system for ventilating clean rooms in a hospital around an operating table. The ventilated air forms a bounded space using a perforated ceiling in the space to supply the air through a slot line and then exhausting the air through outlets near the floor of the room. The Lada U.S. Pat. No. 3,897,229, is a dual action laminar air flow system in which air inlets are located in the upper portion with exhaust openings located in a lower portion of the system. The Miline U.S. Pat. No. 4,576,613, is a process for combining the pollution in an area with the aid of a gaseous jet for the confinement of areas containing toxic or radioactive materials and uses gas jets on opposite sides of an area to confine the radioactive materials.
In contrast, the present chemical control system is used for confining volatile fluids around a dry cleaning machine and can be installed as a framework around the dry cleaning equipment to provide a low pressure air discharge from the top portion and fluid intake pipes at the lower portion of the dry cleaning equipment to form a predefined air flow which can be readily modified as to shape and size of the confinement area and which provides not only filtering of the fluids but electronic sensors for controlling the system and a catch basin below the equipment for the handling of spilled liquids, as well as an underground system for confining and cleaning the soil beneath the floor of the building.